1. Field of the Invention
This invention relates to a self-tapping threaded insert for use in mounting another component on a member on which the insert is mounted, to an insert assembly of the insert and the member on which it is mounted, and to a method for mounting the insert on the member.
2. Background Art
One way in which components are mounted on a member in industrial assembly utilizes a threaded insert that is threaded into the member and has a threaded connector on which another threaded component can be mounted by threading. Such a construction permits mounting and removal of the component as may be required for maintenance, repair or replacement.
Prior art references noted during an investigation in connection with the present invention include U.S. Pat. Nos.: 3,789,725 Lindstrom; 3,942,406 Egner; 4,003,287 Ziaylek, Jr.; 4,449,874 McKinney; 4,673,323 Russo; 5,000,639 Hinkley et al.; 5,071,301 Engelhardt et al.; and 5,211,520 McKinney.
An object of the present invention is to provide an improved self-tapping threaded insert for use in mounting another component on a member on which the insert is mounted.
In carrying out the above object, the insert of the invention includes a threaded shank that has a central axis and a uniform diameter thread as well as having a tapered end with a tapered thread. The tapered end of the threaded shank has at least two circumferentially spaced flutes that extend to and terminate at the uniform diameter thread of the threaded shank. Each flute has a pair of flat surfaces extending perpendicular to each other and having a junction that extends angularly to the central axis of the threaded shank. A locking flange of the insert extends outwardly from the threaded shank and has a locking surface that faces toward the tapered end of the shank to provide locking against an opposed surface of the member on which the insert is mounted. The locking flange has drive surfaces for providing torquing of the insert for mounting and removal. A central connector of the insert extends from the locking flange and has a thread for securing another component to the insert and the member on which it is mounted.
In the preferred construction, the tapered end of the threaded shank has four circumferentially spaced flutes that extend to and terminate at the uniform diameter of the threaded shank. Each of the four flutes has a pair of flat surfaces extending perpendicular to each other and having a junction that extends angularly to the central axis of the threaded shank.
In one preferred embodiment of the self-tapping threaded insert, the central connector is a threaded hole that extends within the threaded shank toward the tapered end of the threaded shank. This embodiment has the locking flange provided with a drive face in which the drive surfaces are located, and the drive face is oriented in the opposite direction as the locking surface of the locking flange.
In another preferred embodiment of the self-tapping threaded insert, the central connector is a threaded stud that extends from the locking flange along the central axis away from the threaded shank. This embodiment has the drive surfaces of the locking flange facing radially outward from the central axis axially between the threaded shank and the threaded stud.
Another object of the present invention is to provide an improved insert assembly.
In carrying out the immediately preceding object, the improved insert assembly of the invention includes a member having a surface through which a partially tapped hole extends. The partially tapped hole has a uniform diameter thread with a plurality of turns and also has a tapered thread that extends from the uniform diameter thread. A self-tapping threaded insert of the assembly has a threaded shank with a central axis and a uniform diameter thread with more turns and of a slightly larger diameter than the uniform diameter of the partially tapped hole so as to have full engagement therewith upon threading into the partially threaded hole. The threaded shank has a tapered thread that extends from its uniform diameter thread. The tapered end of the threaded shank has at least two circumferentially spaced flutes that extend to and terminate at the uniform diameter thread of the threaded shank, and each flute has a pair of flat surfaces extending perpendicular to each other and having a junction that extends angularly to the central axis of the threaded shank. The insert has a locking flange that extends outwardly from the threaded shank. This locking flange has a locking surface that faces toward the tapered end of the shank to provide locking against the surface of the member as the insert is threaded into the partially threaded hole. The locking flange has drive surfaces for providing torquing of the insert for mounting on and removal from the member. The insert also has a central connector that extends from the locking flange and has a thread for securing another component to the insert and the member on which it is mounted.
Another object of the present invention is to provide an improved method for mounting a self-tapping threaded insert.
In carrying out the immediately preceding object, the method for mounting a self-tapping threaded insert in accordance with the invention is performed by partially tapping a hole through a surface in a member such that the hole has a uniform diameter thread with a plurality of turns and also has a tapered thread that extends from the uniform diameter thread. A tapered end of a threaded shank of a self-tapping threaded insert is inserted into the partially tapped hole with the tapered end of the insert having at least two circumferentially spaced flutes that extend to and terminate at a uniform diameter of the threaded shank and with each flute having a pair of flat surfaces that extend perpendicular to each other and have a junction that extends angularly to a central axis of the threaded shank. The insert is threaded into the partially tapped hole such that the uniform diameter thread of the shank, which has more turns and is of a slightly larger diameter than the uniform diameter of the partially tapped hole, and the tapered end of the threaded shank are completely engaged with the hole. The insert is torqued at drive surfaces of a locking flange of the insert such that a locking surface of the locking flange locks against the surface of the insert as the insert is fully threaded into the hole to mount the insert with a central connector thereof extending from the locking flange and having a thread for securing another component to the insert and the member on which it is mounted.
The objects, features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.